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4c039060 | 1 | /************************************************************************** |
2 | * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * | |
3 | * * | |
4 | * Author: The ALICE Off-line Project. * | |
5 | * Contributors are mentioned in the code where appropriate. * | |
6 | * * | |
7 | * Permission to use, copy, modify and distribute this software and its * | |
8 | * documentation strictly for non-commercial purposes is hereby granted * | |
9 | * without fee, provided that the above copyright notice appears in all * | |
10 | * copies and that both the copyright notice and this permission notice * | |
11 | * appear in the supporting documentation. The authors make no claims * | |
12 | * about the suitability of this software for any purpose. It is * | |
13 | * provided "as is" without express or implied warranty. * | |
14 | **************************************************************************/ | |
15 | ||
88cb7938 | 16 | /* $Id$ */ |
4c039060 | 17 | |
030b4415 | 18 | //////////////////////////////////////////////////////////////////////////// |
19 | // // | |
20 | // Transition Radiation Detector version 1 -- slow simulator // | |
21 | // // | |
22 | //////////////////////////////////////////////////////////////////////////// | |
fe4da5cc | 23 | |
769257f4 | 24 | #include <stdlib.h> |
25 | ||
793ff80c | 26 | #include <TF1.h> |
1819f4bb | 27 | #include <TLorentzVector.h> |
88cb7938 | 28 | #include <TMath.h> |
29 | #include <TRandom.h> | |
30 | #include <TVector.h> | |
31 | #include <TVirtualMC.h> | |
f57bb418 | 32 | #include <TGeoManager.h> |
268f57b1 | 33 | #include <TGeoMatrix.h> |
170c35f1 | 34 | #include <TGeoPhysicalNode.h> |
fe4da5cc | 35 | |
d3f347ff | 36 | #include "AliConst.h" |
45160b1f | 37 | #include "AliLog.h" |
e6add757 | 38 | #include "AliTrackReference.h" |
45160b1f | 39 | #include "AliMC.h" |
88cb7938 | 40 | #include "AliRun.h" |
02cb65d6 | 41 | #include "AliGeomManager.h" |
030b4415 | 42 | |
88cb7938 | 43 | #include "AliTRDgeometry.h" |
a076fc2f | 44 | #include "AliTRDCommonParam.h" |
793ff80c | 45 | #include "AliTRDhit.h" |
cb2f9e9b | 46 | #include "AliTRDsimTR.h" |
88cb7938 | 47 | #include "AliTRDv1.h" |
851d3db9 | 48 | |
fe4da5cc | 49 | ClassImp(AliTRDv1) |
8230f242 | 50 | |
51 | //_____________________________________________________________________________ | |
030b4415 | 52 | AliTRDv1::AliTRDv1() |
53 | :AliTRD() | |
54 | ,fTRon(kFALSE) | |
55 | ,fTR(NULL) | |
56 | ,fTypeOfStepManager(0) | |
57 | ,fStepSize(0) | |
f2979d08 | 58 | ,fWion(0) |
030b4415 | 59 | ,fDeltaE(NULL) |
60 | ,fDeltaG(NULL) | |
61 | ,fTrackLength0(0) | |
62 | ,fPrimaryTrackPid(0) | |
8230f242 | 63 | { |
64 | // | |
65 | // Default constructor | |
66 | // | |
67 | ||
8230f242 | 68 | } |
69 | ||
fe4da5cc | 70 | //_____________________________________________________________________________ |
71 | AliTRDv1::AliTRDv1(const char *name, const char *title) | |
030b4415 | 72 | :AliTRD(name,title) |
73 | ,fTRon(kTRUE) | |
74 | ,fTR(NULL) | |
67c47633 | 75 | ,fTypeOfStepManager(2) |
030b4415 | 76 | ,fStepSize(0.1) |
f2979d08 | 77 | ,fWion(0) |
030b4415 | 78 | ,fDeltaE(NULL) |
79 | ,fDeltaG(NULL) | |
80 | ,fTrackLength0(0) | |
81 | ,fPrimaryTrackPid(0) | |
fe4da5cc | 82 | { |
83 | // | |
851d3db9 | 84 | // Standard constructor for Transition Radiation Detector version 1 |
fe4da5cc | 85 | // |
82bbf98a | 86 | |
5c7f4665 | 87 | SetBufferSize(128000); |
88 | ||
a076fc2f | 89 | if (AliTRDCommonParam::Instance()->IsXenon()) { |
f2979d08 | 90 | fWion = 23.53; // Ionization energy XeCO2 (85/15) |
91 | } | |
a076fc2f | 92 | else if (AliTRDCommonParam::Instance()->IsArgon()) { |
f2979d08 | 93 | fWion = 27.21; // Ionization energy ArCO2 (82/18) |
94 | } | |
95 | else { | |
96 | AliFatal("Wrong gas mixture"); | |
97 | exit(1); | |
98 | } | |
99 | ||
5c7f4665 | 100 | } |
101 | ||
102 | //_____________________________________________________________________________ | |
103 | AliTRDv1::~AliTRDv1() | |
104 | { | |
dd9a6ee3 | 105 | // |
106 | // AliTRDv1 destructor | |
107 | // | |
82bbf98a | 108 | |
030b4415 | 109 | if (fDeltaE) { |
110 | delete fDeltaE; | |
111 | fDeltaE = 0; | |
112 | } | |
113 | ||
114 | if (fDeltaG) { | |
115 | delete fDeltaG; | |
116 | fDeltaG = 0; | |
117 | } | |
118 | ||
119 | if (fTR) { | |
120 | delete fTR; | |
121 | fTR = 0; | |
122 | } | |
82bbf98a | 123 | |
fe4da5cc | 124 | } |
125 | ||
f57bb418 | 126 | //_____________________________________________________________________________ |
127 | void AliTRDv1::AddAlignableVolumes() const | |
128 | { | |
129 | // | |
130 | // Create entries for alignable volumes associating the symbolic volume | |
131 | // name with the corresponding volume path. Needs to be syncronized with | |
132 | // eventual changes in the geometry. | |
133 | // | |
134 | ||
135 | TString volPath; | |
136 | TString symName; | |
137 | ||
92cd97ad | 138 | TString vpStr = "ALIC_1/B077_1/BSEGMO"; |
139 | TString vpApp1 = "_1/BTRD"; | |
140 | TString vpApp2 = "_1"; | |
141 | TString vpApp3a = "/UTR1_1/UTS1_1/UTI1_1/UT"; | |
142 | TString vpApp3b = "/UTR2_1/UTS2_1/UTI2_1/UT"; | |
143 | TString vpApp3c = "/UTR3_1/UTS3_1/UTI3_1/UT"; | |
f57bb418 | 144 | |
92cd97ad | 145 | TString snStr = "TRD/sm"; |
146 | TString snApp1 = "/st"; | |
147 | TString snApp2 = "/pl"; | |
f57bb418 | 148 | |
149 | // | |
150 | // The super modules | |
151 | // The symbolic names are: TRD/sm00 | |
152 | // ... | |
153 | // TRD/sm17 | |
154 | // | |
053767a4 | 155 | for (Int_t isector = 0; isector < AliTRDgeometry::Nsector(); isector++) { |
f57bb418 | 156 | |
157 | volPath = vpStr; | |
053767a4 | 158 | volPath += isector; |
f57bb418 | 159 | volPath += vpApp1; |
053767a4 | 160 | volPath += isector; |
f57bb418 | 161 | volPath += vpApp2; |
162 | ||
163 | symName = snStr; | |
053767a4 | 164 | symName += Form("%02d",isector); |
f57bb418 | 165 | |
166 | gGeoManager->SetAlignableEntry(symName.Data(),volPath.Data()); | |
167 | ||
168 | } | |
169 | ||
170 | // | |
171 | // The readout chambers | |
172 | // The symbolic names are: TRD/sm00/st0/pl0 | |
173 | // ... | |
174 | // TRD/sm17/st4/pl5 | |
175 | // | |
02cb65d6 | 176 | AliGeomManager::ELayerID idTRD1 = AliGeomManager::kTRD1; |
177 | Int_t layer, modUID; | |
178 | ||
053767a4 | 179 | for (Int_t isector = 0; isector < AliTRDgeometry::Nsector(); isector++) { |
8bf0cd64 | 180 | |
053767a4 | 181 | if (fGeometry->GetSMstatus(isector) == 0) continue; |
8bf0cd64 | 182 | |
053767a4 | 183 | for (Int_t istack = 0; istack < AliTRDgeometry::Nstack(); istack++) { |
184 | for (Int_t ilayer = 0; ilayer < AliTRDgeometry::Nlayer(); ilayer++) { | |
f57bb418 | 185 | |
053767a4 | 186 | layer = idTRD1 + ilayer; |
187 | modUID = AliGeomManager::LayerToVolUIDSafe(layer,isector*5+istack); | |
188 | ||
189 | Int_t idet = AliTRDgeometry::GetDetectorSec(ilayer,istack); | |
f57bb418 | 190 | |
191 | volPath = vpStr; | |
053767a4 | 192 | volPath += isector; |
f57bb418 | 193 | volPath += vpApp1; |
053767a4 | 194 | volPath += isector; |
f57bb418 | 195 | volPath += vpApp2; |
053767a4 | 196 | switch (isector) { |
92cd97ad | 197 | case 13: |
198 | case 14: | |
199 | case 15: | |
053767a4 | 200 | if (istack == 2) { |
92cd97ad | 201 | continue; |
202 | } | |
203 | volPath += vpApp3c; | |
204 | break; | |
205 | case 11: | |
206 | case 12: | |
207 | volPath += vpApp3b; | |
208 | break; | |
209 | default: | |
210 | volPath += vpApp3a; | |
211 | }; | |
f57bb418 | 212 | volPath += Form("%02d",idet); |
213 | volPath += vpApp2; | |
214 | ||
215 | symName = snStr; | |
053767a4 | 216 | symName += Form("%02d",isector); |
f57bb418 | 217 | symName += snApp1; |
053767a4 | 218 | symName += istack; |
f57bb418 | 219 | symName += snApp2; |
053767a4 | 220 | symName += ilayer; |
f57bb418 | 221 | |
51a5f1d0 | 222 | TGeoPNEntry *alignableEntry = |
02cb65d6 | 223 | gGeoManager->SetAlignableEntry(symName.Data(),volPath.Data(),modUID); |
f57bb418 | 224 | |
170c35f1 | 225 | // Add the tracking to local matrix following the TPC example |
51a5f1d0 | 226 | if (alignableEntry) { |
02cb65d6 | 227 | TGeoHMatrix *globMatrix = alignableEntry->GetGlobalOrig(); |
053767a4 | 228 | Double_t sectorAngle = 20.0 * (isector % 18) + 10.0; |
51a5f1d0 | 229 | TGeoHMatrix *t2lMatrix = new TGeoHMatrix(); |
230 | t2lMatrix->RotateZ(sectorAngle); | |
231 | t2lMatrix->MultiplyLeft(&(globMatrix->Inverse())); | |
232 | alignableEntry->SetMatrix(t2lMatrix); | |
233 | } | |
234 | else { | |
235 | AliError(Form("Alignable entry %s is not valid!",symName.Data())); | |
236 | } | |
8bf0cd64 | 237 | |
f57bb418 | 238 | } |
239 | } | |
240 | } | |
241 | ||
242 | } | |
243 | ||
fe4da5cc | 244 | //_____________________________________________________________________________ |
245 | void AliTRDv1::CreateGeometry() | |
246 | { | |
247 | // | |
851d3db9 | 248 | // Create the GEANT geometry for the Transition Radiation Detector - Version 1 |
5c7f4665 | 249 | // This version covers the full azimuth. |
d3f347ff | 250 | // |
251 | ||
82bbf98a | 252 | // Check that FRAME is there otherwise we have no place where to put the TRD |
8230f242 | 253 | AliModule* frame = gAlice->GetModule("FRAME"); |
030b4415 | 254 | if (!frame) { |
255 | AliError("TRD needs FRAME to be present\n"); | |
256 | return; | |
257 | } | |
d3f347ff | 258 | |
82bbf98a | 259 | // Define the chambers |
260 | AliTRD::CreateGeometry(); | |
d3f347ff | 261 | |
fe4da5cc | 262 | } |
263 | ||
264 | //_____________________________________________________________________________ | |
265 | void AliTRDv1::CreateMaterials() | |
266 | { | |
267 | // | |
851d3db9 | 268 | // Create materials for the Transition Radiation Detector version 1 |
fe4da5cc | 269 | // |
82bbf98a | 270 | |
d3f347ff | 271 | AliTRD::CreateMaterials(); |
82bbf98a | 272 | |
fe4da5cc | 273 | } |
274 | ||
793ff80c | 275 | //_____________________________________________________________________________ |
276 | void AliTRDv1::CreateTRhit(Int_t det) | |
277 | { | |
278 | // | |
279 | // Creates an electron cluster from a TR photon. | |
280 | // The photon is assumed to be created a the end of the radiator. The | |
281 | // distance after which it deposits its energy takes into account the | |
282 | // absorbtion of the entrance window and of the gas mixture in drift | |
283 | // volume. | |
284 | // | |
285 | ||
793ff80c | 286 | // Maximum number of TR photons per track |
287 | const Int_t kNTR = 50; | |
288 | ||
030b4415 | 289 | TLorentzVector mom; |
290 | TLorentzVector pos; | |
793ff80c | 291 | |
ce0d6231 | 292 | Float_t eTR[kNTR]; |
293 | Int_t nTR; | |
793ff80c | 294 | |
ce0d6231 | 295 | // Create TR photons |
296 | gMC->TrackMomentum(mom); | |
297 | Float_t pTot = mom.Rho(); | |
298 | fTR->CreatePhotons(11,pTot,nTR,eTR); | |
299 | if (nTR > kNTR) { | |
300 | AliFatal(Form("Boundary error: nTR = %d, kNTR = %d",nTR,kNTR)); | |
301 | } | |
f73816f5 | 302 | |
ce0d6231 | 303 | // Loop through the TR photons |
304 | for (Int_t iTR = 0; iTR < nTR; iTR++) { | |
793ff80c | 305 | |
ce0d6231 | 306 | Float_t energyMeV = eTR[iTR] * 0.001; |
307 | Float_t energyeV = eTR[iTR] * 1000.0; | |
308 | Float_t absLength = 0.0; | |
309 | Float_t sigma = 0.0; | |
793ff80c | 310 | |
ce0d6231 | 311 | // Take the absorbtion in the entrance window into account |
312 | Double_t muMy = fTR->GetMuMy(energyMeV); | |
313 | sigma = muMy * fFoilDensity; | |
314 | if (sigma > 0.0) { | |
315 | absLength = gRandom->Exp(1.0/sigma); | |
316 | if (absLength < AliTRDgeometry::MyThick()) { | |
842287f2 | 317 | continue; |
318 | } | |
ce0d6231 | 319 | } |
320 | else { | |
321 | continue; | |
322 | } | |
793ff80c | 323 | |
ce0d6231 | 324 | // The absorbtion cross sections in the drift gas |
325 | // Gas-mixture (Xe/CO2) | |
f2979d08 | 326 | Double_t muNo = 0.0; |
a076fc2f | 327 | if (AliTRDCommonParam::Instance()->IsXenon()) { |
f2979d08 | 328 | muNo = fTR->GetMuXe(energyMeV); |
329 | } | |
a076fc2f | 330 | else if (AliTRDCommonParam::Instance()->IsArgon()) { |
f2979d08 | 331 | muNo = fTR->GetMuAr(energyMeV); |
332 | } | |
ce0d6231 | 333 | Double_t muCO = fTR->GetMuCO(energyMeV); |
f2979d08 | 334 | sigma = (fGasNobleFraction * muNo + (1.0 - fGasNobleFraction) * muCO) |
335 | * fGasDensity | |
336 | * fTR->GetTemp(); | |
ce0d6231 | 337 | |
338 | // The distance after which the energy of the TR photon | |
339 | // is deposited. | |
340 | if (sigma > 0.0) { | |
341 | absLength = gRandom->Exp(1.0/sigma); | |
342 | if (absLength > (AliTRDgeometry::DrThick() | |
343 | + AliTRDgeometry::AmThick())) { | |
842287f2 | 344 | continue; |
345 | } | |
ce0d6231 | 346 | } |
347 | else { | |
348 | continue; | |
349 | } | |
793ff80c | 350 | |
ce0d6231 | 351 | // The position of the absorbtion |
352 | Float_t posHit[3]; | |
353 | gMC->TrackPosition(pos); | |
354 | posHit[0] = pos[0] + mom[0] / pTot * absLength; | |
355 | posHit[1] = pos[1] + mom[1] / pTot * absLength; | |
356 | posHit[2] = pos[2] + mom[2] / pTot * absLength; | |
793ff80c | 357 | |
ce0d6231 | 358 | // Create the charge |
f2979d08 | 359 | Int_t q = ((Int_t) (energyeV / fWion)); |
793ff80c | 360 | |
ce0d6231 | 361 | // Add the hit to the array. TR photon hits are marked |
362 | // by negative charge | |
363 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() | |
364 | ,det | |
365 | ,posHit | |
366 | ,-q | |
25ca55ce | 367 | ,gMC->TrackTime()*1.0e06 |
d4c6453d | 368 | ,kTRUE); |
793ff80c | 369 | |
370 | } | |
371 | ||
372 | } | |
373 | ||
5c7f4665 | 374 | //_____________________________________________________________________________ |
375 | void AliTRDv1::Init() | |
376 | { | |
377 | // | |
378 | // Initialise Transition Radiation Detector after geometry has been built. | |
5c7f4665 | 379 | // |
380 | ||
381 | AliTRD::Init(); | |
382 | ||
45160b1f | 383 | AliDebug(1,"Slow simulator\n"); |
bd0f8685 | 384 | |
385 | // Switch on TR simulation as default | |
386 | if (!fTRon) { | |
45160b1f | 387 | AliInfo("TR simulation off"); |
bd0f8685 | 388 | } |
389 | else { | |
cb2f9e9b | 390 | fTR = new AliTRDsimTR(); |
bd0f8685 | 391 | } |
5c7f4665 | 392 | |
f2979d08 | 393 | // First ionization potential (eV) for the gas mixture |
5c7f4665 | 394 | const Float_t kPoti = 12.1; |
395 | // Maximum energy (50 keV); | |
396 | const Float_t kEend = 50000.0; | |
397 | // Ermilova distribution for the delta-ray spectrum | |
030b4415 | 398 | Float_t poti = TMath::Log(kPoti); |
399 | Float_t eEnd = TMath::Log(kEend); | |
a328fff9 | 400 | |
401 | // Ermilova distribution for the delta-ray spectrum | |
c4214bc0 | 402 | fDeltaE = new TF1("deltae" ,Ermilova ,poti,eEnd,0); |
a328fff9 | 403 | |
404 | // Geant3 distribution for the delta-ray spectrum | |
c4214bc0 | 405 | fDeltaG = new TF1("deltag",IntSpecGeant,2.421257,28.536469,0); |
5c7f4665 | 406 | |
45160b1f | 407 | AliDebug(1,"+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++"); |
5c7f4665 | 408 | |
fe4da5cc | 409 | } |
410 | ||
5c7f4665 | 411 | //_____________________________________________________________________________ |
412 | void AliTRDv1::StepManager() | |
a328fff9 | 413 | { |
414 | // | |
c4214bc0 | 415 | // Slow simulator. Every charged track produces electron cluster as hits |
a328fff9 | 416 | // along its path across the drift volume. |
417 | // | |
418 | ||
419 | switch (fTypeOfStepManager) { | |
a6dd11e9 | 420 | case 0: |
421 | StepManagerErmilova(); | |
422 | break; | |
423 | case 1: | |
424 | StepManagerGeant(); | |
425 | break; | |
426 | case 2: | |
427 | StepManagerFixedStep(); | |
428 | break; | |
429 | default: | |
430 | AliWarning("Not a valid Step Manager."); | |
a328fff9 | 431 | } |
432 | ||
433 | } | |
434 | ||
435 | //_____________________________________________________________________________ | |
436 | void AliTRDv1::SelectStepManager(Int_t t) | |
437 | { | |
438 | // | |
439 | // Selects a step manager type: | |
440 | // 0 - Ermilova | |
441 | // 1 - Geant3 | |
442 | // 2 - Fixed step size | |
443 | // | |
444 | ||
a328fff9 | 445 | fTypeOfStepManager = t; |
45160b1f | 446 | AliInfo(Form("Step Manager type %d was selected",fTypeOfStepManager)); |
a328fff9 | 447 | |
448 | } | |
449 | ||
450 | //_____________________________________________________________________________ | |
451 | void AliTRDv1::StepManagerGeant() | |
452 | { | |
453 | // | |
c4214bc0 | 454 | // Slow simulator. Every charged track produces electron cluster as hits |
a328fff9 | 455 | // along its path across the drift volume. The step size is set acording |
456 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
457 | // a spectrum taken from Geant3. | |
458 | // | |
f2979d08 | 459 | // Works only for Xe/CO2!! |
460 | // | |
f2e3a0b5 | 461 | // Version by A. Bercuci |
462 | // | |
463 | ||
053767a4 | 464 | Int_t layer = 0; |
465 | Int_t stack = 0; | |
466 | Int_t sector = 0; | |
467 | Int_t det = 0; | |
c4214bc0 | 468 | Int_t iPdg; |
469 | Int_t qTot; | |
470 | ||
471 | Float_t hits[3]; | |
472 | Float_t charge; | |
473 | Float_t aMass; | |
474 | ||
030b4415 | 475 | Double_t pTot = 0; |
c4214bc0 | 476 | Double_t eDelta; |
030b4415 | 477 | Double_t betaGamma; |
478 | Double_t pp; | |
f2e3a0b5 | 479 | Double_t stepSize = 0; |
c4214bc0 | 480 | |
481 | Bool_t drRegion = kFALSE; | |
482 | Bool_t amRegion = kFALSE; | |
483 | ||
2c8bf4aa | 484 | TString cIdPath; |
485 | Char_t cIdSector[3]; | |
486 | cIdSector[2] = 0; | |
487 | ||
c4214bc0 | 488 | TString cIdCurrent; |
489 | TString cIdSensDr = "J"; | |
490 | TString cIdSensAm = "K"; | |
491 | Char_t cIdChamber[3]; | |
492 | cIdChamber[2] = 0; | |
493 | ||
030b4415 | 494 | TLorentzVector pos; |
495 | TLorentzVector mom; | |
c4214bc0 | 496 | |
030b4415 | 497 | TArrayI processes; |
f2e3a0b5 | 498 | |
053767a4 | 499 | const Int_t kNlayer = AliTRDgeometry::Nlayer(); |
500 | const Int_t kNstack = AliTRDgeometry::Nstack(); | |
501 | const Int_t kNdetsec = kNlayer * kNstack; | |
c4214bc0 | 502 | |
030b4415 | 503 | const Double_t kBig = 1.0e+12; // Infinitely big |
c4214bc0 | 504 | const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g |
505 | ||
506 | // Minimum energy for the step size adjustment | |
507 | const Float_t kEkinMinStep = 1.0e-5; | |
508 | // energy threshold for production of delta electrons | |
f2e3a0b5 | 509 | const Float_t kECut = 1.0e4; |
510 | // Parameters entering the parametrized range for delta electrons | |
030b4415 | 511 | const Float_t kRa = 5.37e-4; |
f2e3a0b5 | 512 | const Float_t kRb = 0.9815; |
030b4415 | 513 | const Float_t kRc = 3.123e-3; |
f2e3a0b5 | 514 | // Gas density -> To be made user adjustable ! |
030b4415 | 515 | // [0.85*0.00549+0.15*0.00186 (Xe-CO2 85-15)] |
516 | const Float_t kRho = 0.004945 ; | |
a328fff9 | 517 | |
c4214bc0 | 518 | // Plateau value of the energy-loss for electron in xenon |
030b4415 | 519 | // The averaged value (26/3/99) |
c4214bc0 | 520 | const Float_t kPlateau = 1.55; |
030b4415 | 521 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) |
522 | const Float_t kPrim = 19.34; | |
c4214bc0 | 523 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) |
524 | const Float_t kPoti = 12.1; | |
030b4415 | 525 | // PDG code electron |
526 | const Int_t kPdgElectron = 11; | |
c4214bc0 | 527 | |
528 | // Set the maximum step size to a very large number for all | |
529 | // neutral particles and those outside the driftvolume | |
530 | gMC->SetMaxStep(kBig); | |
531 | ||
532 | // Use only charged tracks | |
533 | if (( gMC->TrackCharge() ) && | |
c4214bc0 | 534 | (!gMC->IsTrackDisappeared())) { |
535 | ||
536 | // Inside a sensitive volume? | |
537 | drRegion = kFALSE; | |
538 | amRegion = kFALSE; | |
539 | cIdCurrent = gMC->CurrentVolName(); | |
540 | if (cIdSensDr == cIdCurrent[1]) { | |
541 | drRegion = kTRUE; | |
542 | } | |
543 | if (cIdSensAm == cIdCurrent[1]) { | |
544 | amRegion = kTRUE; | |
545 | } | |
546 | if (drRegion || amRegion) { | |
a328fff9 | 547 | |
c4214bc0 | 548 | // The hit coordinates and charge |
549 | gMC->TrackPosition(pos); | |
550 | hits[0] = pos[0]; | |
551 | hits[1] = pos[1]; | |
552 | hits[2] = pos[2]; | |
553 | ||
2c8bf4aa | 554 | // The sector number (0 - 17), according to standard coordinate system |
555 | cIdPath = gGeoManager->GetPath(); | |
556 | cIdSector[0] = cIdPath[21]; | |
557 | cIdSector[1] = cIdPath[22]; | |
053767a4 | 558 | sector = atoi(cIdSector); |
c4214bc0 | 559 | |
053767a4 | 560 | // The layer and stack number |
030b4415 | 561 | cIdChamber[0] = cIdCurrent[2]; |
562 | cIdChamber[1] = cIdCurrent[3]; | |
c4214bc0 | 563 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); |
053767a4 | 564 | stack = ((Int_t) idChamber / kNlayer); |
565 | layer = ((Int_t) idChamber % kNlayer); | |
c4214bc0 | 566 | |
ce0d6231 | 567 | // The detector number |
053767a4 | 568 | det = fGeometry->GetDetector(layer,stack,sector); |
c4214bc0 | 569 | |
ce0d6231 | 570 | // Special hits only in the drift region |
571 | if ((drRegion) && | |
572 | (gMC->IsTrackEntering())) { | |
c4214bc0 | 573 | |
ce0d6231 | 574 | // Create a track reference at the entrance of each |
575 | // chamber that contains the momentum components of the particle | |
576 | gMC->TrackMomentum(mom); | |
e6add757 | 577 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber(), AliTrackReference::kTRD); |
c4214bc0 | 578 | |
ce0d6231 | 579 | // Create the hits from TR photons if electron/positron is |
580 | // entering the drift volume | |
581 | if ((fTR) && | |
582 | (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) { | |
f2979d08 | 583 | CreateTRhit(det); |
ce0d6231 | 584 | } |
f2e3a0b5 | 585 | |
ce0d6231 | 586 | } |
587 | else if ((amRegion) && | |
588 | (gMC->IsTrackExiting())) { | |
f2e3a0b5 | 589 | |
ce0d6231 | 590 | // Create a track reference at the exit of each |
591 | // chamber that contains the momentum components of the particle | |
592 | gMC->TrackMomentum(mom); | |
e6add757 | 593 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber(), AliTrackReference::kTRD); |
c4214bc0 | 594 | |
ce0d6231 | 595 | } |
c4214bc0 | 596 | |
ce0d6231 | 597 | // Calculate the energy of the delta-electrons |
598 | // modified by Alex Bercuci (A.Bercuci@gsi.de) on 26.01.06 | |
599 | // take into account correlation with the underlying GEANT tracking | |
600 | // mechanism. see | |
601 | // http://www-linux.gsi.de/~abercuci/Contributions/TRD/index.html | |
602 | // | |
603 | // determine the most significant process (last on the processes list) | |
604 | // which caused this hit | |
605 | gMC->StepProcesses(processes); | |
606 | Int_t nofprocesses = processes.GetSize(); | |
607 | Int_t pid; | |
608 | if (!nofprocesses) { | |
609 | pid = 0; | |
610 | } | |
611 | else { | |
053767a4 | 612 | pid = processes[nofprocesses-1]; |
ce0d6231 | 613 | } |
f2e3a0b5 | 614 | |
ce0d6231 | 615 | // Generate Edep according to GEANT parametrisation |
616 | eDelta = TMath::Exp(fDeltaG->GetRandom()) - kPoti; | |
617 | eDelta = TMath::Max(eDelta,0.0); | |
618 | Float_t prRange = 0.0; | |
619 | Float_t range = gMC->TrackLength() - fTrackLength0; | |
620 | // merge GEANT tracker information with locally cooked one | |
621 | if (gAlice->GetMCApp()->GetCurrentTrackNumber() == fPrimaryTrackPid) { | |
622 | if (pid == 27) { | |
623 | if (eDelta >= kECut) { | |
624 | prRange = kRa * eDelta * 0.001 | |
625 | * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho; | |
626 | if (prRange >= (3.7 - range)) { | |
627 | eDelta *= 0.1; | |
628 | } | |
629 | } | |
630 | } | |
631 | else if (pid == 1) { | |
632 | if (eDelta < kECut) { | |
633 | eDelta *= 0.5; | |
634 | } | |
635 | else { | |
636 | prRange = kRa * eDelta * 0.001 | |
637 | * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho; | |
638 | if (prRange >= ((AliTRDgeometry::DrThick() | |
639 | + AliTRDgeometry::AmThick()) - range)) { | |
640 | eDelta *= 0.05; | |
641 | } | |
642 | else { | |
f2e3a0b5 | 643 | eDelta *= 0.5; |
ce0d6231 | 644 | } |
645 | } | |
646 | } | |
f2e3a0b5 | 647 | else { |
648 | eDelta = 0.0; | |
ce0d6231 | 649 | } |
650 | } | |
651 | else { | |
652 | eDelta = 0.0; | |
653 | } | |
c4214bc0 | 654 | |
ce0d6231 | 655 | // Generate the electron cluster size |
656 | if (eDelta > 0.0) { | |
f2e3a0b5 | 657 | |
f2979d08 | 658 | qTot = ((Int_t) (eDelta / fWion) + 1); |
ce0d6231 | 659 | |
660 | // Create a new dEdx hit | |
030b4415 | 661 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
662 | ,det | |
663 | ,hits | |
664 | ,qTot | |
25ca55ce | 665 | ,gMC->TrackTime()*1.0e06 |
030b4415 | 666 | ,drRegion); |
c4214bc0 | 667 | |
ce0d6231 | 668 | } |
669 | ||
670 | // Calculate the maximum step size for the next tracking step | |
671 | // Produce only one hit if Ekin is below cutoff | |
672 | aMass = gMC->TrackMass(); | |
673 | if ((gMC->Etot() - aMass) > kEkinMinStep) { | |
674 | ||
675 | // The energy loss according to Bethe Bloch | |
676 | iPdg = TMath::Abs(gMC->TrackPid()); | |
677 | if ((iPdg != kPdgElectron) || | |
678 | ((iPdg == kPdgElectron) && | |
679 | (pTot < kPTotMaxEl))) { | |
680 | gMC->TrackMomentum(mom); | |
681 | pTot = mom.Rho(); | |
682 | betaGamma = pTot / aMass; | |
683 | pp = BetheBlochGeant(betaGamma); | |
684 | // Take charge > 1 into account | |
685 | charge = gMC->TrackCharge(); | |
686 | if (TMath::Abs(charge) > 1) { | |
687 | pp = pp * charge*charge; | |
688 | } | |
689 | } | |
690 | else { | |
691 | // Electrons above 20 Mev/c are at the plateau | |
692 | pp = kPrim * kPlateau; | |
693 | } | |
f2e3a0b5 | 694 | |
ce0d6231 | 695 | Int_t nsteps = 0; |
696 | do { | |
697 | nsteps = gRandom->Poisson(pp); | |
698 | } while(!nsteps); | |
699 | stepSize = 1.0 / nsteps; | |
700 | gMC->SetMaxStep(stepSize); | |
f2e3a0b5 | 701 | |
c4214bc0 | 702 | } |
f2e3a0b5 | 703 | |
c4214bc0 | 704 | } |
f2e3a0b5 | 705 | |
c4214bc0 | 706 | } |
f2e3a0b5 | 707 | |
a328fff9 | 708 | } |
709 | ||
710 | //_____________________________________________________________________________ | |
711 | void AliTRDv1::StepManagerErmilova() | |
5c7f4665 | 712 | { |
713 | // | |
5c7f4665 | 714 | // Slow simulator. Every charged track produces electron cluster as hits |
715 | // along its path across the drift volume. The step size is set acording | |
716 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
717 | // a spectrum taken from Ermilova et al. | |
718 | // | |
f2979d08 | 719 | // Works only for Xe/CO2!! |
720 | // | |
5c7f4665 | 721 | |
053767a4 | 722 | Int_t layer = 0; |
723 | Int_t stack = 0; | |
724 | Int_t sector = 0; | |
725 | Int_t det = 0; | |
851d3db9 | 726 | Int_t iPdg; |
793ff80c | 727 | Int_t qTot; |
5c7f4665 | 728 | |
793ff80c | 729 | Float_t hits[3]; |
a5cadd36 | 730 | Double_t random[1]; |
5c7f4665 | 731 | Float_t charge; |
732 | Float_t aMass; | |
733 | ||
030b4415 | 734 | Double_t pTot = 0.0; |
5c7f4665 | 735 | Double_t eDelta; |
030b4415 | 736 | Double_t betaGamma; |
737 | Double_t pp; | |
f73816f5 | 738 | Double_t stepSize; |
5c7f4665 | 739 | |
332e9569 | 740 | Bool_t drRegion = kFALSE; |
741 | Bool_t amRegion = kFALSE; | |
742 | ||
2c8bf4aa | 743 | TString cIdPath; |
744 | Char_t cIdSector[3]; | |
745 | cIdSector[2] = 0; | |
746 | ||
332e9569 | 747 | TString cIdCurrent; |
748 | TString cIdSensDr = "J"; | |
749 | TString cIdSensAm = "K"; | |
593a9fc3 | 750 | Char_t cIdChamber[3]; |
751 | cIdChamber[2] = 0; | |
332e9569 | 752 | |
030b4415 | 753 | TLorentzVector pos; |
754 | TLorentzVector mom; | |
82bbf98a | 755 | |
053767a4 | 756 | const Int_t kNlayer = AliTRDgeometry::Nlayer(); |
757 | const Int_t kNstack = AliTRDgeometry::Nstack(); | |
758 | const Int_t kNdetsec = kNlayer * kNstack; | |
e644678a | 759 | |
030b4415 | 760 | const Double_t kBig = 1.0e+12; // Infinitely big |
a328fff9 | 761 | const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g |
5c7f4665 | 762 | |
f73816f5 | 763 | // Minimum energy for the step size adjustment |
764 | const Float_t kEkinMinStep = 1.0e-5; | |
a328fff9 | 765 | |
5c7f4665 | 766 | // Plateau value of the energy-loss for electron in xenon |
030b4415 | 767 | // The averaged value (26/3/99) |
a3c76cdc | 768 | const Float_t kPlateau = 1.55; |
030b4415 | 769 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) |
770 | const Float_t kPrim = 48.0; | |
5c7f4665 | 771 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) |
a3c76cdc | 772 | const Float_t kPoti = 12.1; |
030b4415 | 773 | // PDG code electron |
774 | const Int_t kPdgElectron = 11; | |
5c7f4665 | 775 | |
776 | // Set the maximum step size to a very large number for all | |
777 | // neutral particles and those outside the driftvolume | |
778 | gMC->SetMaxStep(kBig); | |
779 | ||
780 | // Use only charged tracks | |
781 | if (( gMC->TrackCharge() ) && | |
5c7f4665 | 782 | (!gMC->IsTrackDisappeared())) { |
fe4da5cc | 783 | |
5c7f4665 | 784 | // Inside a sensitive volume? |
332e9569 | 785 | drRegion = kFALSE; |
786 | amRegion = kFALSE; | |
787 | cIdCurrent = gMC->CurrentVolName(); | |
e6674585 | 788 | if (cIdSensDr == cIdCurrent[1]) { |
332e9569 | 789 | drRegion = kTRUE; |
790 | } | |
e6674585 | 791 | if (cIdSensAm == cIdCurrent[1]) { |
332e9569 | 792 | amRegion = kTRUE; |
793 | } | |
794 | if (drRegion || amRegion) { | |
fe4da5cc | 795 | |
5c7f4665 | 796 | // The hit coordinates and charge |
797 | gMC->TrackPosition(pos); | |
798 | hits[0] = pos[0]; | |
799 | hits[1] = pos[1]; | |
800 | hits[2] = pos[2]; | |
5c7f4665 | 801 | |
2c8bf4aa | 802 | // The sector number (0 - 17), according to standard coordinate system |
803 | cIdPath = gGeoManager->GetPath(); | |
804 | cIdSector[0] = cIdPath[21]; | |
805 | cIdSector[1] = cIdPath[22]; | |
053767a4 | 806 | sector = atoi(cIdSector); |
82bbf98a | 807 | |
332e9569 | 808 | // The plane and chamber number |
809 | cIdChamber[0] = cIdCurrent[2]; | |
810 | cIdChamber[1] = cIdCurrent[3]; | |
e644678a | 811 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); |
053767a4 | 812 | stack = ((Int_t) idChamber / kNlayer); |
813 | layer = ((Int_t) idChamber % kNlayer); | |
82bbf98a | 814 | |
ce0d6231 | 815 | // The detector number |
053767a4 | 816 | det = fGeometry->GetDetector(layer,stack,sector); |
5c7f4665 | 817 | |
ce0d6231 | 818 | // Special hits only in the drift region |
819 | if ((drRegion) && | |
820 | (gMC->IsTrackEntering())) { | |
5c7f4665 | 821 | |
ce0d6231 | 822 | // Create a track reference at the entrance of each |
823 | // chamber that contains the momentum components of the particle | |
824 | gMC->TrackMomentum(mom); | |
e6add757 | 825 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber(), AliTrackReference::kTRD); |
793ff80c | 826 | |
ce0d6231 | 827 | // Create the hits from TR photons if electron/positron is |
828 | // entering the drift volume | |
829 | if ((fTR) && | |
830 | (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) { | |
f2979d08 | 831 | CreateTRhit(det); |
ce0d6231 | 832 | } |
f73816f5 | 833 | |
ce0d6231 | 834 | } |
835 | else if ((amRegion) && | |
836 | (gMC->IsTrackExiting())) { | |
f73816f5 | 837 | |
ce0d6231 | 838 | // Create a track reference at the exit of each |
839 | // chamber that contains the momentum components of the particle | |
840 | gMC->TrackMomentum(mom); | |
e6add757 | 841 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber(), AliTrackReference::kTRD); |
f73816f5 | 842 | |
ce0d6231 | 843 | } |
844 | ||
845 | // Calculate the energy of the delta-electrons | |
846 | eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti; | |
847 | eDelta = TMath::Max(eDelta,0.0); | |
848 | ||
849 | // Generate the electron cluster size | |
850 | if (eDelta > 0.0) { | |
851 | ||
f2979d08 | 852 | qTot = ((Int_t) (eDelta / fWion) + 1); |
f73816f5 | 853 | |
030b4415 | 854 | // Create a new dEdx hit |
332e9569 | 855 | if (drRegion) { |
a328fff9 | 856 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
030b4415 | 857 | ,det |
858 | ,hits | |
859 | ,qTot | |
25ca55ce | 860 | ,gMC->TrackTime()*1.0e06 |
030b4415 | 861 | ,kTRUE); |
862 | } | |
5c7f4665 | 863 | else { |
a328fff9 | 864 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
030b4415 | 865 | ,det |
866 | ,hits | |
867 | ,qTot | |
25ca55ce | 868 | ,gMC->TrackTime()*1.0e06 |
030b4415 | 869 | ,kFALSE); |
870 | } | |
f73816f5 | 871 | |
ce0d6231 | 872 | } |
873 | ||
874 | // Calculate the maximum step size for the next tracking step | |
875 | // Produce only one hit if Ekin is below cutoff | |
876 | aMass = gMC->TrackMass(); | |
877 | if ((gMC->Etot() - aMass) > kEkinMinStep) { | |
878 | ||
879 | // The energy loss according to Bethe Bloch | |
880 | iPdg = TMath::Abs(gMC->TrackPid()); | |
881 | if ((iPdg != kPdgElectron) || | |
882 | ((iPdg == kPdgElectron) && | |
883 | (pTot < kPTotMaxEl))) { | |
884 | gMC->TrackMomentum(mom); | |
885 | pTot = mom.Rho(); | |
886 | betaGamma = pTot / aMass; | |
887 | pp = kPrim * BetheBloch(betaGamma); | |
888 | // Take charge > 1 into account | |
889 | charge = gMC->TrackCharge(); | |
890 | if (TMath::Abs(charge) > 1) { | |
891 | pp = pp * charge*charge; | |
f73816f5 | 892 | } |
ce0d6231 | 893 | } |
894 | else { | |
895 | // Electrons above 20 Mev/c are at the plateau | |
896 | pp = kPrim * kPlateau; | |
897 | } | |
f73816f5 | 898 | |
ce0d6231 | 899 | if (pp > 0.0) { |
900 | do { | |
901 | gMC->GetRandom()->RndmArray(1,random); | |
030b4415 | 902 | } |
ce0d6231 | 903 | while ((random[0] == 1.0) || |
904 | (random[0] == 0.0)); | |
905 | stepSize = - TMath::Log(random[0]) / pp; | |
906 | gMC->SetMaxStep(stepSize); | |
907 | } | |
030b4415 | 908 | |
5c7f4665 | 909 | } |
030b4415 | 910 | |
d3f347ff | 911 | } |
030b4415 | 912 | |
5c7f4665 | 913 | } |
030b4415 | 914 | |
5c7f4665 | 915 | } |
916 | ||
a328fff9 | 917 | //_____________________________________________________________________________ |
918 | void AliTRDv1::StepManagerFixedStep() | |
919 | { | |
920 | // | |
921 | // Slow simulator. Every charged track produces electron cluster as hits | |
922 | // along its path across the drift volume. The step size is fixed in | |
923 | // this version of the step manager. | |
924 | // | |
f2979d08 | 925 | // Works for Xe/CO2 as well as Ar/CO2 |
926 | // | |
a328fff9 | 927 | |
ce0d6231 | 928 | // PDG code electron |
929 | const Int_t kPdgElectron = 11; | |
930 | ||
053767a4 | 931 | Int_t layer = 0; |
932 | Int_t stack = 0; | |
933 | Int_t sector = 0; | |
934 | Int_t det = 0; | |
a328fff9 | 935 | Int_t qTot; |
936 | ||
937 | Float_t hits[3]; | |
938 | Double_t eDep; | |
939 | ||
940 | Bool_t drRegion = kFALSE; | |
941 | Bool_t amRegion = kFALSE; | |
942 | ||
2c8bf4aa | 943 | TString cIdPath; |
944 | Char_t cIdSector[3]; | |
945 | cIdSector[2] = 0; | |
946 | ||
a328fff9 | 947 | TString cIdCurrent; |
948 | TString cIdSensDr = "J"; | |
949 | TString cIdSensAm = "K"; | |
950 | Char_t cIdChamber[3]; | |
2c8bf4aa | 951 | cIdChamber[2] = 0; |
a328fff9 | 952 | |
030b4415 | 953 | TLorentzVector pos; |
954 | TLorentzVector mom; | |
a328fff9 | 955 | |
053767a4 | 956 | const Int_t kNlayer = AliTRDgeometry::Nlayer(); |
957 | const Int_t kNstack = AliTRDgeometry::Nstack(); | |
958 | const Int_t kNdetsec = kNlayer * kNstack; | |
a328fff9 | 959 | |
030b4415 | 960 | const Double_t kBig = 1.0e+12; |
a328fff9 | 961 | const Float_t kEkinMinStep = 1.0e-5; // Minimum energy for the step size adjustment |
962 | ||
963 | // Set the maximum step size to a very large number for all | |
964 | // neutral particles and those outside the driftvolume | |
965 | gMC->SetMaxStep(kBig); | |
966 | ||
967 | // If not charged track or already stopped or disappeared, just return. | |
968 | if ((!gMC->TrackCharge()) || | |
ce0d6231 | 969 | gMC->IsTrackDisappeared()) { |
970 | return; | |
971 | } | |
a328fff9 | 972 | |
973 | // Inside a sensitive volume? | |
974 | cIdCurrent = gMC->CurrentVolName(); | |
975 | ||
ce0d6231 | 976 | if (cIdSensDr == cIdCurrent[1]) { |
977 | drRegion = kTRUE; | |
978 | } | |
979 | if (cIdSensAm == cIdCurrent[1]) { | |
980 | amRegion = kTRUE; | |
981 | } | |
a328fff9 | 982 | |
030b4415 | 983 | if ((!drRegion) && |
984 | (!amRegion)) { | |
985 | return; | |
986 | } | |
a328fff9 | 987 | |
988 | // The hit coordinates and charge | |
989 | gMC->TrackPosition(pos); | |
990 | hits[0] = pos[0]; | |
991 | hits[1] = pos[1]; | |
992 | hits[2] = pos[2]; | |
993 | ||
2c8bf4aa | 994 | // The sector number (0 - 17), according to standard coordinate system |
995 | cIdPath = gGeoManager->GetPath(); | |
996 | cIdSector[0] = cIdPath[21]; | |
997 | cIdSector[1] = cIdPath[22]; | |
053767a4 | 998 | sector = atoi(cIdSector); |
a328fff9 | 999 | |
1000 | // The plane and chamber number | |
030b4415 | 1001 | cIdChamber[0] = cIdCurrent[2]; |
1002 | cIdChamber[1] = cIdCurrent[3]; | |
a328fff9 | 1003 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); |
053767a4 | 1004 | stack = ((Int_t) idChamber / kNlayer); |
1005 | layer = ((Int_t) idChamber % kNlayer); | |
e0d47c25 | 1006 | |
030b4415 | 1007 | // The detector number |
053767a4 | 1008 | det = fGeometry->GetDetector(layer,stack,sector); |
030b4415 | 1009 | |
25ca55ce | 1010 | // 0: InFlight 1:Entering 2:Exiting |
030b4415 | 1011 | Int_t trkStat = 0; |
a328fff9 | 1012 | |
1013 | // Special hits only in the drift region | |
ce0d6231 | 1014 | if ((drRegion) && |
1015 | (gMC->IsTrackEntering())) { | |
a328fff9 | 1016 | |
ce0d6231 | 1017 | // Create a track reference at the entrance of each |
1018 | // chamber that contains the momentum components of the particle | |
1019 | gMC->TrackMomentum(mom); | |
e6add757 | 1020 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber(), AliTrackReference::kTRD); |
ce0d6231 | 1021 | trkStat = 1; |
a328fff9 | 1022 | |
ce0d6231 | 1023 | // Create the hits from TR photons if electron/positron is |
1024 | // entering the drift volume | |
1025 | if ((fTR) && | |
1026 | (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) { | |
f2979d08 | 1027 | CreateTRhit(det); |
030b4415 | 1028 | } |
a328fff9 | 1029 | |
ce0d6231 | 1030 | } |
1031 | else if ((amRegion) && | |
1032 | (gMC->IsTrackExiting())) { | |
1033 | ||
1034 | // Create a track reference at the exit of each | |
1035 | // chamber that contains the momentum components of the particle | |
1036 | gMC->TrackMomentum(mom); | |
e6add757 | 1037 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber(), AliTrackReference::kTRD); |
ce0d6231 | 1038 | trkStat = 2; |
1039 | ||
a328fff9 | 1040 | } |
1041 | ||
1042 | // Calculate the charge according to GEANT Edep | |
1043 | // Create a new dEdx hit | |
1044 | eDep = TMath::Max(gMC->Edep(),0.0) * 1.0e+09; | |
f2979d08 | 1045 | qTot = (Int_t) (eDep / fWion); |
ce0d6231 | 1046 | if ((qTot) || |
1047 | (trkStat)) { | |
1048 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() | |
1049 | ,det | |
1050 | ,hits | |
1051 | ,qTot | |
25ca55ce | 1052 | ,gMC->TrackTime()*1.0e06 |
ce0d6231 | 1053 | ,drRegion); |
1054 | } | |
a328fff9 | 1055 | |
1056 | // Set Maximum Step Size | |
1057 | // Produce only one hit if Ekin is below cutoff | |
030b4415 | 1058 | if ((gMC->Etot() - gMC->TrackMass()) < kEkinMinStep) { |
1059 | return; | |
1060 | } | |
a328fff9 | 1061 | gMC->SetMaxStep(fStepSize); |
1062 | ||
1063 | } | |
1064 | ||
5c7f4665 | 1065 | //_____________________________________________________________________________ |
1066 | Double_t AliTRDv1::BetheBloch(Double_t bg) | |
1067 | { | |
1068 | // | |
1069 | // Parametrization of the Bethe-Bloch-curve | |
1070 | // The parametrization is the same as for the TPC and is taken from Lehrhaus. | |
1071 | // | |
1072 | ||
1073 | // This parameters have been adjusted to averaged values from GEANT | |
f57bb418 | 1074 | const Double_t kP1 = 7.17960e-02; |
1075 | const Double_t kP2 = 8.54196; | |
1076 | const Double_t kP3 = 1.38065e-06; | |
1077 | const Double_t kP4 = 5.30972; | |
1078 | const Double_t kP5 = 2.83798; | |
5c7f4665 | 1079 | |
f73816f5 | 1080 | // Lower cutoff of the Bethe-Bloch-curve to limit step sizes |
1081 | const Double_t kBgMin = 0.8; | |
1082 | const Double_t kBBMax = 6.83298; | |
f73816f5 | 1083 | |
1084 | if (bg > kBgMin) { | |
030b4415 | 1085 | Double_t yy = bg / TMath::Sqrt(1.0 + bg*bg); |
5c7f4665 | 1086 | Double_t aa = TMath::Power(yy,kP4); |
030b4415 | 1087 | Double_t bb = TMath::Power((1.0/bg),kP5); |
5c7f4665 | 1088 | bb = TMath::Log(kP3 + bb); |
030b4415 | 1089 | return ((kP2 - aa - bb) * kP1 / aa); |
5c7f4665 | 1090 | } |
f73816f5 | 1091 | else { |
1092 | return kBBMax; | |
1093 | } | |
d3f347ff | 1094 | |
fe4da5cc | 1095 | } |
5c7f4665 | 1096 | |
a328fff9 | 1097 | //_____________________________________________________________________________ |
c4214bc0 | 1098 | Double_t AliTRDv1::BetheBlochGeant(Double_t bg) |
a328fff9 | 1099 | { |
1100 | // | |
1101 | // Return dN/dx (number of primary collisions per centimeter) | |
1102 | // for given beta*gamma factor. | |
1103 | // | |
1104 | // Implemented by K.Oyama according to GEANT 3 parametrization shown in | |
1105 | // A.Andronic's webpage: http://www-alice.gsi.de/trd/papers/dedx/dedx.html | |
1106 | // This must be used as a set with IntSpecGeant. | |
1107 | // | |
1108 | ||
030b4415 | 1109 | Int_t i = 0; |
a328fff9 | 1110 | |
030b4415 | 1111 | Double_t arrG[20] = { 1.100000, 1.200000, 1.300000, 1.500000 |
1112 | , 1.800000, 2.000000, 2.500000, 3.000000 | |
1113 | , 4.000000, 7.000000, 10.000000, 20.000000 | |
1114 | , 40.000000, 70.000000, 100.000000, 300.000000 | |
1115 | , 600.000000, 1000.000000, 3000.000000, 10000.000000 }; | |
a328fff9 | 1116 | |
030b4415 | 1117 | Double_t arrNC[20] = { 75.009056, 45.508083, 35.299252, 27.116327 |
1118 | , 22.734999, 21.411915, 19.934095, 19.449375 | |
1119 | , 19.344431, 20.185553, 21.027925, 22.912676 | |
1120 | , 24.933352, 26.504053, 27.387468, 29.566597 | |
1121 | , 30.353779, 30.787134, 31.129285, 31.157350 }; | |
1122 | ||
1123 | // Betagamma to gamma | |
1124 | Double_t g = TMath::Sqrt(1.0 + bg*bg); | |
a328fff9 | 1125 | |
1126 | // Find the index just before the point we need. | |
030b4415 | 1127 | for (i = 0; i < 18; i++) { |
1128 | if ((arrG[i] < g) && | |
1129 | (arrG[i+1] > g)) { | |
a328fff9 | 1130 | break; |
030b4415 | 1131 | } |
1132 | } | |
a328fff9 | 1133 | |
1134 | // Simple interpolation. | |
030b4415 | 1135 | Double_t pp = ((arrNC[i+1] - arrNC[i]) / (arrG[i+1] - arrG[i])) |
1136 | * (g - arrG[i]) + arrNC[i]; | |
a328fff9 | 1137 | |
030b4415 | 1138 | return pp; |
a328fff9 | 1139 | |
1140 | } | |
1141 | ||
5c7f4665 | 1142 | //_____________________________________________________________________________ |
1143 | Double_t Ermilova(Double_t *x, Double_t *) | |
1144 | { | |
1145 | // | |
1146 | // Calculates the delta-ray energy distribution according to Ermilova. | |
1147 | // Logarithmic scale ! | |
1148 | // | |
1149 | ||
1150 | Double_t energy; | |
1151 | Double_t dpos; | |
1152 | Double_t dnde; | |
1153 | ||
030b4415 | 1154 | Int_t pos1; |
1155 | Int_t pos2; | |
5c7f4665 | 1156 | |
8230f242 | 1157 | const Int_t kNv = 31; |
5c7f4665 | 1158 | |
030b4415 | 1159 | Float_t vxe[kNv] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120 |
1160 | , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052 | |
1161 | , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915 | |
1162 | , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009 | |
1163 | , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103 | |
1164 | , 9.4727, 9.9035, 10.3735, 10.5966, 10.8198 | |
1165 | , 11.5129 }; | |
1166 | ||
1167 | Float_t vye[kNv] = { 80.0, 31.0, 23.3, 21.1, 21.0 | |
1168 | , 20.9, 20.8, 20.0, 16.0, 11.0 | |
1169 | , 8.0, 6.0, 5.2, 4.6, 4.0 | |
1170 | , 3.5, 3.0, 1.4, 0.67, 0.44 | |
1171 | , 0.3, 0.18, 0.12, 0.08, 0.056 | |
1172 | , 0.04, 0.023, 0.015, 0.011, 0.01 | |
1173 | , 0.004 }; | |
5c7f4665 | 1174 | |
1175 | energy = x[0]; | |
1176 | ||
1177 | // Find the position | |
030b4415 | 1178 | pos1 = 0; |
1179 | pos2 = 0; | |
5c7f4665 | 1180 | dpos = 0; |
1181 | do { | |
1182 | dpos = energy - vxe[pos2++]; | |
1183 | } | |
1184 | while (dpos > 0); | |
1185 | pos2--; | |
030b4415 | 1186 | if (pos2 > kNv) { |
1187 | pos2 = kNv - 1; | |
1188 | } | |
5c7f4665 | 1189 | pos1 = pos2 - 1; |
1190 | ||
1191 | // Differentiate between the sampling points | |
1192 | dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]); | |
1193 | ||
1194 | return dnde; | |
1195 | ||
1196 | } | |
a328fff9 | 1197 | |
1198 | //_____________________________________________________________________________ | |
1199 | Double_t IntSpecGeant(Double_t *x, Double_t *) | |
1200 | { | |
1201 | // | |
1202 | // Integrated spectrum from Geant3 | |
1203 | // | |
1204 | ||
96efaf83 | 1205 | const Int_t npts = 83; |
030b4415 | 1206 | Double_t arre[npts] = { 2.421257, 2.483278, 2.534301, 2.592230 |
1207 | , 2.672067, 2.813299, 3.015059, 3.216819 | |
1208 | , 3.418579, 3.620338, 3.868209, 3.920198 | |
1209 | , 3.978284, 4.063923, 4.186264, 4.308605 | |
1210 | , 4.430946, 4.553288, 4.724261, 4.837736 | |
1211 | , 4.999842, 5.161949, 5.324056, 5.486163 | |
1212 | , 5.679688, 5.752998, 5.857728, 5.962457 | |
1213 | , 6.067185, 6.171914, 6.315653, 6.393674 | |
1214 | , 6.471694, 6.539689, 6.597658, 6.655627 | |
1215 | , 6.710957, 6.763648, 6.816338, 6.876198 | |
1216 | , 6.943227, 7.010257, 7.106285, 7.252151 | |
1217 | , 7.460531, 7.668911, 7.877290, 8.085670 | |
1218 | , 8.302979, 8.353585, 8.413120, 8.483500 | |
1219 | , 8.541030, 8.592857, 8.668865, 8.820485 | |
1220 | , 9.037086, 9.253686, 9.470286, 9.686887 | |
1221 | , 9.930838, 9.994655, 10.085822, 10.176990 | |
1222 | , 10.268158, 10.359325, 10.503614, 10.627565 | |
1223 | , 10.804637, 10.981709, 11.158781, 11.335854 | |
1224 | , 11.593397, 11.781165, 12.049404, 12.317644 | |
1225 | , 12.585884, 12.854123, 14.278421, 16.975889 | |
1226 | , 20.829416, 24.682943, 28.536469 }; | |
1227 | ||
1228 | Double_t arrdnde[npts] = { 10.960000, 10.960000, 10.359500, 9.811340 | |
1229 | , 9.1601500, 8.206670, 6.919630, 5.655430 | |
1230 | , 4.6221300, 3.777610, 3.019560, 2.591950 | |
1231 | , 2.5414600, 2.712920, 3.327460, 4.928240 | |
1232 | , 7.6185300, 10.966700, 12.225800, 8.094750 | |
1233 | , 3.3586900, 1.553650, 1.209600, 1.263840 | |
1234 | , 1.3241100, 1.312140, 1.255130, 1.165770 | |
1235 | , 1.0594500, 0.945450, 0.813231, 0.699837 | |
1236 | , 0.6235580, 2.260990, 2.968350, 2.240320 | |
1237 | , 1.7988300, 1.553300, 1.432070, 1.535520 | |
1238 | , 1.4429900, 1.247990, 1.050750, 0.829549 | |
1239 | , 0.5900280, 0.395897, 0.268741, 0.185320 | |
1240 | , 0.1292120, 0.103545, 0.0949525, 0.101535 | |
1241 | , 0.1276380, 0.134216, 0.123816, 0.104557 | |
1242 | , 0.0751843, 0.0521745, 0.0373546, 0.0275391 | |
1243 | , 0.0204713, 0.0169234, 0.0154552, 0.0139194 | |
1244 | , 0.0125592, 0.0113638, 0.0107354, 0.0102137 | |
1245 | , 0.00845984, 0.00683338, 0.00556836, 0.00456874 | |
1246 | , 0.0036227, 0.00285991, 0.00226664, 0.00172234 | |
1247 | , 0.00131226, 0.00100284, 0.000465492, 7.26607e-05 | |
1248 | , 3.63304e-06, 0.0000000, 0.0000000 }; | |
1249 | ||
1250 | Int_t i; | |
a328fff9 | 1251 | Double_t energy = x[0]; |
a328fff9 | 1252 | |
225211c8 | 1253 | if (energy >= arre[npts-1]) { |
1254 | return 0.0; | |
1255 | } | |
1256 | ||
030b4415 | 1257 | for (i = 0; i < npts; i++) { |
1258 | if (energy < arre[i]) { | |
1259 | break; | |
1260 | } | |
1261 | } | |
a328fff9 | 1262 | |
030b4415 | 1263 | if (i == 0) { |
1264 | AliErrorGeneral("AliTRDv1::IntSpecGeant","Given energy value is too small or zero"); | |
1265 | } | |
a328fff9 | 1266 | |
f57bb418 | 1267 | return arrdnde[i]; |
a328fff9 | 1268 | |
1269 | } |